Directional aerial



. DIRECTIONAL AERIAL Filed Dec. 3, 1930 INVENTOR FRED WOODS ATTORNEYPatented Mar. 12, 1935 '5 s PATENT OFFICE 1,9943% k DIRECTIONAL AERmFred Woods, Richmond, Surrey, England, assignor to Radio Corporation ofAmerica, a corporation of Delaware UNITED STATE.

Application December 3, 1930,-Seri al No. 499,619

111 Great Britain December 12, 1929 "8 Claims. (01. 250-33 Thisinvention relates to directional aerial sys windings are similarlybrought down inside the temsand, although not limited to its applicationpedestal. v thereto, is 'particularly suitable for use in con- When itis desired to take directional readings, nection with direction findinginstallations on the connection point for the screen system is leftboard ship. earthed or insulated, i.'e., unconnected, and the 5 Asiswell known, it is common practice in direcaerials are utilized in theusual way.. When it tion finding installations toprovide a directionalis desired to take sense readings the connection aerial system forascertaining the direction of a point for the screen system is connectedto earth received signal and an additional open aerial for throughanappropriate phasing circuit by any ascertaining the sense of thatdirection. In convenient form of switch gear.

many-places, for example, on board ship,' the Preferably the frameaerials, pedestal, leads, additional open aerial'constitutes'an'undesirable and associated amplifier are provided withconcomplication since it occupies valuable room and 1711111011 ScreeningSuch Screening is y y is sometimes difiicult to install satisfactorily.to efiect in the described construction, for ex -Accordingto thisinvention, a directional aerial ample, as shown in Figure 2, by takingthe leads 15;

system comprises directional frame aerial windat the base. of thepedestal through a hole 15 in ings for ascertaining thedirectionof areceived the side thereof, and through a screening tube 16 signal andmeans cons'tituted by a screen'or to. the usual. screened amplifierv1'7, the tube, screens about said directional frame aerialwindamplifier screen and pedestal being thus con- 20 ings forascertaining the sense of said directinuous and totally enclosing theelectrical cir- 20 tion. cuits and connections. The invention isillustrated in the accompany- It is found. that with such continuity ofscreening schematic drawing in which Figure 1 shows ing comparativeimmunity m' nduction and one general arrangement in accordance with thisother. electrical noises is obtained since with the invention, whileFigure 2 shows apreferred detail describedarrangement all points of thescreening 25 modification suitable for incorporation at the y e are maai ed a SubStant aHy-the'same base f the pedestal. which forms rt of thappaelectrical level; It is not in practice necessary to ratus shown inFigure 1, earth the screens though, of course, this may in Referring toFigure 1, this shows a form of some cases be desirable if convenient.Again construction as applied to a so-called Belliniwith such screens itis not in practice necessary Tosi frame aerial system suitable for useon ship t at t p d s should be mounted upo insulaboard. Apparatuscomprises a hollow pedestal tion though again this may be founddesirable 1 mounted upon insulating material 2 and carryif convenient. iing on the top a directional aerial system con- Having nowparticularlyxdescribed and ascersisting of a pair-of mutuallyperpendicular coils tained the nature of my said invention and in 3, 4,as usually provided in the well known what manner the same'is to beperformed, I de- Bellini-Tosi system. The mutually perpendicuclare thatwhat I claim is:- lar coils are enclosed within and screened by u Signalabsorption yst inc udmetal and preferably weatherproof tubes 5, 6 of ingmeans for insuring t the energy a sorbed 40 usual construction which areconnected together thereby Wi l b truly Characteristic of the y at thetop where they cross and are ins lated tems position relative to thesource of said sigfrom one another at the bottom where they cross. 1181sComprising, tW0 Closed windings Of a D The top junction point of thetubular screens is rality of turns, a Screen Comprising metallicconstituted by a suitable boxlike structure 7 tubes arranged at rightangles t a h the COmwhichserves to provide mechanical support for the pet ly enclosing each of Said windings, Seldscreens, said boxlikestructure carrying a downtallic tubes completely electrostaticallyshielding wardly projecting rod 8 which terminates at its said windingsand substantially completely end in a similar boxlike structure'9 whichsupp y y enclosing Said Wind-ings, Said w g which they are insulatedfrom one another. The rotatably mounting said screen on an insulated rodis connected down through the pedestal to a base, means for connectingsaid closed windings connection point 10 which thus constitutes eleC- toa receiving set, and means for obtaining a vertrically the connectionpointof the screen system. tical aerial effect comprising a centralmetallic 55 The leads .1 2, 1 1 from h di i fin ing rod forming a leadsymmetrically connected to 55 ports the coil screens at their lowercrossing at being open to magnetic lines of force, means for .i saidscreen and symmetrically arranged with respect to said first namedleads.

2. A directional aerial system comprising two directional loop aerialsenclosed within metallic tubes, said tubes mounted upon a hollowmetallic pedestal, both tubes and pedestal comprising an electricalshieldfor said directional aerial system, said loop aerials arranged atright angles to each other, the lower portion of said loop 'aerial.being supported on said hollow metallic pedestal by a box-likeinsulating member, and an upper metallic box-like member providing ajunction point for said loop aerials, said upper k V atright angles toeach other, the lower portion- "of said loop aerials being supported onsaid holmember having a depending metallic rod; said rod beingmechanically secure but electrically insulated from said lowerinsulating member.

3. A directional aerial system' comprising (a pair of crossed frameclosed aerial windings,

shielding means for said windings comprising,

metallic tubes electrically and mechanically conne'cted together-atonecrossing-point and electrically insulated but mechanically securedtogether at'the' other o'rossin'glpoint, means for connecting saidwindings to a receiver, and a metal rod passing diametrically across theframe closed aerials'and between the two crossing points 'thereof,said'metal'rod being mechanically secured but electrically insulated fromthe last mentioned crossing point so as'to act as a lead for saidshielding means. v I 4. A directional aerial system comprising twodirective loop 'aerials arranged at right angles to each other andenclosed within metallic tubes, said tubes being mounted on a hollowmetallic pedestal, both tubes and said pedestal comprising an electricalshield for said directional aerial system, 'an' amplifier for saidsystem, a plurality of connectingleads for connecting said loops and theamplifier passing through said pedestal,

means for providing a vertical aerial 'efiect for said system,comprising a central. lead electrically connected to the top of saidloops and mechanicallyxsec'ured but electrically'insulated at the bottomof said loops and passing through said pedestal and symmetricallydisposed with respect. to the first mentioned leads so as to provide thevertical aerial efiectfor said directional system; l

'5. A directional aerial system comprising two directional loopaerialsarranged atright angles to each other and enclosed withinmetallic tubes, said vtubesmounted upon a.- hollo.w metallic pedestal,one of said loops being alarger. diameter than the other, both tubes andpedestal comprising an electrical shield for said directional aerialsystem, the lower portion of said loop aerial being supported on saidhollow metallic pedestal by a box-like insulating member, and an uppermetallic box-like member providing a junction point for said loopaerials, said upper member having a depending metallic rod, said rodbeing mechanically secure but electrically insulated from said lowerinsulating member. V 5 6. A directional aerial system comprising twodirectional loop aerials enclosedwithin metallic tubes, said tubes beingmounted upon aj hollow metallic pedestalfboth tubes and'pedestal comprising an electrical shield for said directional aerial system, aplurality of connecting leads for connecting said loops with a receiverand passing through said pedestaLsaid loop aerials arranged member, andan upper'metallic box-like member providing a junction point for saidloop aerials, said upper member having a depending metallic rod, saidrod being mechanically secure but electrically' insulated from saidlower insulating member and passing through a central portion ofsaidpedestal so, as, to besymmetricallyidis posed withrespect to saidfirst.mentioned-leadsa' to provide a vertical aerial effect'tosaidid'irece'z" tional aerial system. 7 I v i 7. A directionalaerialsystem. comprisingqaj" j pair of crossed frame closedaerialg-windings; mountedupon a hollow metallic ,pedestaLlshieldi- 3 ingmeans for said windings comprisingmetallici tubes electrically andmechanically connectedgto gether atone crossing pointand electricallyin-;

sulated but mechanically secured together at the other crossing point, aplurality of connecting; f 35-; 1,

leads for connecting'said, loops with a ,receiver passing throughthelower portion, of said pedes-j tal and a central lead electricallyconnected to}; the upper crossing point of s'aid'loops and me?chanically secured but electrically insulated; 4

pedestal, both tubes and said pedestal comprising l.

anelectrical shield for said directional aerialsysterm, a central leadelectrically connected attire; top of said loops and mechanicallysecured. butelectrically insulated at the bottom 01 fi lid loops V andpassing through the center portion of said pedestal seas to-provide alead for the said elec' trical signal. 1

FRED woonsf

